Apple iPhone, iPad and iPod Touch users are rapidly jumping on board with iOS 8.4. Mixpanel reported more than 40 percent of Apple device owners have installed the latest iOS update a little more than a week after its launch.

Likely contributing to the fast adoption rate was Apple Music and Beats 1. Apple’s new music streaming subscription service and radio station launched with iOS 8.4. There is still plenty of time for its share to grow in coming months. But some of iOS 8.4 adopters could end up going to the iOS 9 public beta, which is expected to launch sometime in July, followed by a full release in the fall.

Mixpanel iOS adoption The current distribution of iOS versions, according to Mixpanel data. Photo: Mixpanel

When iOS 8 was released in September, it saw a similar rapid adoption rate, with 46 percent of Apple devices running the OS by the end of its first week of release, according to Apple Insider. But in the months following the debut, adoption slowed partially due to the large free space requirements for an over-the-air update, the Verge reported. Since then, Apple has improved its updates, reducing sizes of a couple hundred megabytes for most users. As of June 22, iOS 8 total installations accounted for 84 percent of all iOS devices, according to the App Store developer page. It doesn’t break down the installation by individual releases.

Apple adoption rate A graph of total iOS adoption from Apple's developer page. Photo: Apple

By comparison, the total iOS 8 adoption rate continues to lag behind iOS 7, which saw about 89 percent of devices on the OS around the same time after its launch, according to data from Fiksu. Apple’s next major release -- iOS 9 -- will bring a number of new features to iPhones and iPads, such as built-in transit mapping, split-screen multitasking and a News app.